Recording apparatus and method, playback apparatus and method, recording medium, program, and computer-readable recording medium

ABSTRACT

A recording apparatus contains a timer that measures the current time based on a time zone. When writing a VOB onto a DVD, the recording apparatus refers to TM_ZONE recorded on the DVD, and judges whether the time zone which the timer is based on matches the time zone that the TM_ZONE specifies. If the two time zones do not match, the recording apparatus operates as follows. First, the recording apparatus obtains VOB_REC_TM that indicates the recording date/time of the VOB based on TM_ZONE. The recording apparatus then writes the VOB onto the DVD together with VOBI that is information of the VOB and contains (a) the obtained VOB_REC_TM; (b) LOCAL_TZ_TY indicating that the two time zones do not match and (c) LOCAL_TZ specifying the time zone which the timer is based on.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a recording apparatus for recordingpicture data and date/time information onto a recording medium such asan optical disc, a playback apparatus, and a recording medium.

(2) Description of the Related Art

Recording picture data onto a recording medium together with thedate/time information is meaningful. The date/time information helps theuser recall details of the pictures more clearly.

The date/time information is based on a time measured by a timer in therecording apparatus that captures images and records them as picturedata. The time measured by the timer is based on a standard time for theregion where the recording apparatus is used. Such geographic regions onearth to which standard times are assigned are called “time zones”. Atimer in a recording apparatus measures the current time based on thestandard time of the time zone in which the recording apparatus is used.

When picture data is recorded onto a recording medium in a time zone,the date/time information in the recording medium is based on the samestandard time. However, when picture data captured in two or moredifferent time zones is to be recorded onto a recording medium, it isnecessary to select a standard time on which the date/time informationshould be based.

Suppose a user moves from Japan to Country A taking a video-camera typerecording apparatus, and that the time differential between Japan andthe Country A is 12 hours. Here, if the user takes pictures duringdaytime hours in the Country A with the timer being set to the Japanesestandard time, the date/time information recorded on the recordingmedium indicates the nighttime hours due to the time differential. Whenthis happens, the date/time information looses its meaning.

The above problem can be solved if the user sets the timer of therecording apparatus to be based on the standard time of the Country A.Actually, the user can set the timer every time he/she arrives in adifferent time zone. In this case, however, a problem arises concerningthe chronological order of a plurality of pieces of picture data thatare based on different standard times. For example, suppose further thatthe user took a picture in Japan immediately before he/she went to theCountry A and recorded the picture data onto the recording medium, thenit may happen that the date/time information for the picture appears tobe later than that for the picture taken in the Country A. This isbecause the time differential of 12 hours is not taken into account. Ifthese pieces of picture data are sorted in chronological order, theywill be arranged in an improper order. This also makes the date/timeinformation meaningless.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to provide arecording apparatus that provides credibility of the date/timeinformation even if the recording apparatus is used in a plurality oftime zones.

The above object is fulfilled by a recording apparatus that writes avideo object onto a recording medium on which basic time zoneinformation specifying a basic time zone is written, the recordingapparatus comprising: a timer operable to measure a time based on apredetermined time zone; a converting unit operable to, if the basictime zone does not match the predetermined time zone, convert the timemeasured by the timer into a time based on the basic time zone; and awriting unit operable to, if the two time zones do not match, writemanagement information for the video object onto the recording medium,the management information containing a flag indicating that the twotime zones do not match, recording time information showing theconversion-result time, and local time zone information specifying thepredetermined time zone as a local time zone.

With the above-described construction, if the recording apparatus andthe recording medium are based on different time zones, the recordingapparatus generates date/time information based on the time zone for therecording medium and records the generated date/time information ontothe recording medium. As a result, even if two or more video objects arerecorded on the recording medium, the corresponding date/timeinformation is based on the same time zone. When the two or more videoobjects are sorted in chronological order of the recording date/time,they are correctly arranged in the order. Also, if the recordingapparatus and the recording medium are based on different time zones,local time zone information specifying the time zone for the recordingapparatus as a local time zone is recorded onto the recording medium. Byusing the local time zone information to display the date/time when acorresponding a video object is played back, a discrepancy between thecontents of the video object (e.g. captured during daytime hours) andthe displayed recording date/time (e.g. indicating nighttime hours) doesnot happen, keeping the credibility of the date/time information.

BRIEF DESCRIPTION OF THE DRAWINGS

These and the other objects, advantages and features of the inventionwill become apparent from the following description thereof taken inconjunction with the accompanying drawings which illustrate a specificembodiment of the invention.

In the drawings:

FIG. 1 shows a DVD 100 in Embodiment 1 and a recording apparatus 1;

FIG. 2 shows the hierarchical structure of VOBs that are contained inVR_MOVIE.VRO;

FIG. 3 shows the internal structure of VR_MANGR.IFO;

FIG. 4 shows correspondence between VOBs and VOBIs;

FIGS. 5A and 5B show how the recording date/time KHx of picture data Pxis obtained;

FIG. 6 shows the format of VOB_REC_TM;

FIG. 7 shows the construction of TMAPI;

FIG. 8 shows the relationship between TMAPI and VOBU;

FIG. 9 shows the internal structure of VR MANGR.IFO;

FIG. 10 shows relationships between CELLs and VOBs contained in ORGPGCI;

FIG. 11 shows how the CELLs shown in FIG. 9 are assigned to PGs.

FIG. 12 shows RTR_VMGI contained in the management file VR_MANGR.IFO.

FIG. 13 shows how areas in the management file assigned to themanagement tables are specified by the start addresses (M_AVFIT_SAthrough MNFIT_SA) written in the VMGI_MAT and the effective lengths(M_AVFIT_EA through MNFIT_EA) written in the management tables.

FIG. 14 shows time zones for different regions on the earth.

FIG. 15 shows the format of TM_ZONE.

FIGS. 16A, 16B, and 16C show in what timing TM_ZONE is referred to andhow VOB_REC_TM is set by the recording apparatus 1 a in Japan.

FIG. 17 shows a transfer from Japan to U.S.A.

FIG. 18 shows the format of LOCAL_TM_ZONE.

FIGS. 19A, 19B, and 19C show how the recording apparatus 1 b in U.S.A.sets VOB_REC_TM and TM_ZONE.

FIG. 20 shows the internal structure of the recording apparatus 1 inEmbodiment 2.

FIG. 21 is a flowchart showing the operation procedure of the date/timeinformation setting unit 12.

FIG. 22 shows the internal structure of the playback apparatus inEmbodiment 3.

FIG. 23A shows a menu screen on which the user can select either therecording place time mode or the playback place time mode via the userinterface unit 2;

FIG. 23B shows the information stored in the country mark storage unit17;

FIG. 24 is a flowchart showing the operation procedure of the date/timedisplay control unit 20;

FIG. 25 shows an example of the screen displayed by the date/timedisplay control unit 20;

FIG. 26 shows three VOBs recorded in three different time zones: Japan,UK, and U.S.A.;

FIG. 27 shows VOBI that contains the VOB_REC_TMs obtained from FIG. 26;

FIG. 28 shows the internal structure of the playback apparatus inEmbodiment 4;

FIG. 29 shows an example of the volume display generated by the volumedisplay executing unit 21;

FIG. 30 shows the internal structure of UD_PGCIT;

FIG. 31 shows a PL defined in correspondence with the VOBs and TMAPIsshown in FIG. 30;

FIG. 32 shows the internal structure of RTR_VMGI in Embodiment 5;

FIG. 33 shows the internal structure of the playback apparatus inEmbodiment 5;

FIG. 34 shows a menu screen displaying a list of the plurality ofPlayLists recorded on the DVD;

FIGS. 35A and 35B show how VOB portions are specified when VOBs arepartially deleted;

FIG. 36 shows VOBs before and after the partial deletions;

FIGS. 37A and 37B show how VOB_REC_TM and LOCAL_TM_ZONE are set for anew VOB that is created after a middle portion of the old VOB isdeleted;

FIG. 38 shows the file system for DVDs on which VOBs containing stillpicture data (Still_VOBs) are recorded, as well as VOBs containingmoving-picture data;

FIG. 39 shows hierarchical representation of Still_VOBs contained in aVR_STILL.VRO;

FIG. 40 shows the internal structure of the management file inEmbodiment 7;

FIG. 41 shows the internal structure of S_AVFIT; and

FIG. 42 shows an ORG_PGCI that contains information on a moving-picturesection (CELL #1) and a still picture section (CELL #2).

DESCRIPTION OF THE PREFERRED EMBODIMENT

Embodiment 1

The following describes a recording medium as an embodiment of thepresent invention. It is supposed that the recording medium inEmbodiment 1 is a DVD-RAM (hereinafter referred to as DVD) in whichmoving-picture data can be recorded in accordance with the DVD-VIDEORECORDING standard. FIG. 1 shows a DVD 100 in Embodiment 1 and arecording apparatus 1.

The recording apparatus 1 of a camcorder-type captures moving picturesand records the moving-picture data onto the DVD 100 which is housed ina cartridge 101. The DVD 100 has layers such as a physical layer, a filesystem layer, and an application layer. The file system of the DVD 100is shown in FIG. 1, as indicated by a leader line hk1. First, the filestructure of the DVD will be described supposing that only one time zoneis used. As shown in FIG. 1, the file structure includes a DVD_RTAV(RealTime Recording Audio Video) directory that is arranged directlyunder a ROOT directory, and an AV file “VR_MOVIE.VR0” containing VOBsand a management file “VR_MANGR.IFO” containing various types ofmanagement information are arranged under the DVD_RTAV directory, where“VR” is an abbreviation of Video Recording.

FIG. 2 shows the hierarchical structure of VOBs that are contained inthe “VR_MOVIE.VRO” file. The “VR_MOVIE.VRO” file is shown in the seventh(lowest) row in FIG. 2.

The sixth row in FIG. 2 includes the VOBs contained in the “VRMOVIE.VRO” file. FIG. 2 indicates that at least two VOBs, namely VOB#1and VOB#2 are contained in the “VR_MOVIE.VRO” file. Each VOB is aprogram stream conforming to the ISO/IEC13818-1 standard in which avideo stream and an audio stream are multiplexed. The program streams ofthe VOBs differ from general-purpose program streams in that they do notneed to have “program_end_code” at their ends, while it is indispensablefor the general-purpose program streams. The video stream is a sequenceof a plurality of pieces of picture data pi1, pi2, pi3, . . . as shownin the first row of the drawing. The picture data is displayed in unitsof video frames. In the NTSC system, one video frame corresponds to adisplay period of approximately 33 msec (more accurately, 1/29.97 sec),and in the PAL system, one video frame corresponds to a display periodof 40 msec. The picture data is divided into Bidirectionally PredictivePicture (B-Picture) Predictive Picture (P-Picture), and Intra Picture(I-Picture) The B-pictures are compressed using correlation with imagesto be played back before and after the B-pictures (i.e., in the past andfuture directions). The P-pictures are compressed using correlation withimages to be played back before the P-pictures (i.e., in the pastdirection). The I-pictures are compressed using the spatial frequencyresponse for one frame, without using the above correlations.

The smallest unit used in decoding the video streams is GOP (Group OfPicture). Each GOP contains at least one I-Picture, and is a group ofpieces of picture data that corresponds to a playback time ranging from0.4 to 1.0 seconds. For this reason, in FIG. 2, the video stream shownin the first row is divided into a plurality of GOPs shown in the secondrow. The picture data is compressed/encoded by the variable-lengthcoding. Therefore, each GOP has a different data length. When the GOPsequence of the second row is to be recorded onto a DVD, the GOPsequence is divided into a plurality of units each having approximately2 kilobytes regardless of the length of each GOP, as shown in the thirdrow. The units are also referred to as video packs which areinterleave-multiplexed (indicated by “interleave-multiplexing tj1” inFIG. 2) with audio packs having the same size to form the pack sequenceshown in the fourth row. From the pack sequence, the VOBUs (Video ObjectUnits) shown in the fifth row are formed.

Each VOBU contains at least one GOP and audio data. The VOBU is thesmallest access unit of VOBs and is an arranged sequence of video andaudio packs conforming to the MPEG standard. From the VOBU sequence, theVOBs shown in the sixth row are formed.

Now, the internal structure of the management file “VR_MANGR.IFO” willbe described. FIG. 3 shows the internal structure of the management file“VR_MANGR.IFO”. As shown in FIG. 3, the management file “VR_MANGR.IFO”includes RTR_VMGI table (RTR_VMGIT), M_AVFI table (M_AVFIT), ORG_PGCItable (ORG_PGCIT), UD_PGCI table (UD_PGCIT), TXTDT_MG table (TXTDT_MGT),and MNFI table (MNFIT).

The M_AVFI (Motion AV File Information) table is a table used to manageVOBs and includes, as the leader line h3 indicates: VOB_STI_Nsindicating the number of VOB STIs contained in the M_AVFIT; M_AVFIT_EA(Effective Address) indicating the effective length of the M_AVFIT; VOBSTI (Stream Information) #1, . . . VOB STI #K being attributeinformation of VOBs; and M_AVFI. The VOB STI indicates the videoattributes of the picture data (e.g. coding mode, aspect ratio,NTSC/PAL, and line21 information) and audio attributes of the audio data(e.g. coding mode, the number of channels, and frequency) in each VOB.

The M_AVFI includes VOBI #1, . . . VOBI #L, as the leader line h4indicates. The VOBI (Video Object Information) is playback controlinformation unique to each VOB, and includes, as the leader line h5indicates: M_VOB_GI (General Information); and TMAPI (Time MAPInformation) for each VOBU constituting the VOB. The M_VOB_GI includes,as the leader line h6 indicates: VOB_TY indicating the type of the VOB;VOB_REC_TM (VOB Recording TiMe) indicating the year, month, day, hour,minute, second when the first piece of picture data of the VOB wasrecorded; VOB_REC_TM_SUB indicating a fraction of the picture datarecording date/time in a unit that is smaller than second and a videoframe; M_VOB_STIN (Stream Information Number) that specifies one of theVOB STI #1, . . . VOB STI #K, as indicated by the arrow Pr1;VOB_Start_PTM (Presentation TiMe) indicating the time when thepresentation of the first piece of picture data of the VOB starts;VOB_End_PTM indicating the time when the presentation of the last pieceof picture data of the VOB ends; and LOCAL_TM_ZONE.

FIG. 4 shows correspondence between VOBs and VOBIs. As shown in FIG. 4,a VOB and a VOBI corresponding to each other have the same serial numbersuch as #1 and #2. The arrow Pr3 indicates that VOBI #1 and VOBI #2shares stream attribute information “VOB STI #1”, which indicates thatVOB #1 corresponding to VOBI #1 and VOB #2 corresponding to VOBI #2 havethe same image attribute. The VOB_Start_PTMs of the VOBI #1 and VOBI #2indicate, respectively, the times when the presentations of the picturedata Pt1 and Pt3 which are to be displayed first in the first GOPs ofVOBs #1 and #2 start, respectively. The VOB_End_PTMs of the VOBI #1 andVOBI #2 indicate, respectively, the times when the presentations of thepicture data Pt2 and Pt4 which are to be displayed lastly in the lastGOPs of VOBs #1 and #2 end, respectively. A difference between theVOB_End_PTM of VOBI #1 and the VOB_Start_PTM of VOBI #2 is referred toas STC-Offset. The STC (System Time Clock)-Offset is used for theseamless presentation of the two continuous VOBs.

The VOB_REC_TM s of VOBI #1 and VOBI #2 indicate the year, month, day,hour, minute, second when the first pieces of picture data, pt1 and pt3,of VOB #1 and VOB #2 were recorded, respectively. It should be notedhere that in the present embodiment, the pieces of picture data arepresented in the order of recording. This is done for the convenience ofusers. When moving-picture data is compressed using correlation betweenframes, a mismatch between the recording order and the presentationorder occurs. Also, since the picture data is recorded onto the DVDafter it is stored in a buffer, a piece of picture data that wasrecorded first may not necessarily be presented first. If the VOB_REC_TMwas set strictly in accordance with the order in which the picture datawas recorded onto the DVD, the user would feel difficulty in presentingthe recorded data. Taking this into consideration, in the presentembodiment, the VOB_REC_TM is set to the current date/time measured by atimer in a recording apparatus being a camcorder when a capturing unitof the same recording apparatus starts capturing an image.

The VOB_REC_TM will be further described in detail here. The VOB_REC_TMis used to present the recording date/time of picture data to the user.FIGS. 5A and 5B show how the recording date/time is presented to theuser by the recording apparatus using the DVD in the present embodiment.In FIGS. 5A and 5B, “KHx” represents the recording date/time of picturedata Px that was recorded after time x elapsed from the recording starttime. The recording start time equals to the VOB_REC_TM of the VOB. Inthis example, it is supposed that the elapsed time x is 3 minutes. It isalso supposed that the recording elapsed time is equal to thepresentation elapsed time, and actually the presentation elapsed timewhich is obtained from the time indicated by the timer is used for thecalculation. In the present example, the VOB_REC_TM is “2001.11/110:0.00”. Accordingly, the recording date/time KHx “2001.11/1 10:03.00”obtained by adding 3 minutes to the VOB_REC_TM is superimposed onpresentation image GPx corresponding to the picture data Px and ispresented to the user, as shown in FIG. 5B. In this way, the recordingdate/time KHx is obtained and presented for each piece of picture data.This achieves presentation of recording date/time similar to thepresentation of recording data for each image that is provided by acamcorder using video cassette tape as the recording medium.

FIG. 6 shows the format of VOB_REC_TM. As shown in FIG. 6, 6 bits frombit 0 to bit 5 are assigned to “second” (Second[5.0]), 6 bits from bit 6to bit 11 are assigned to “minute” (Minute[1.0], Minute[5.2]), 5 bitsfrom bit 12 to bit 16 are assigned to “hour” (Hour [4], Hour[3.0]), 5bits from bit 17 to bit 21 are assigned to “day” (Day[4.0]), 4 bits frombit 22 to bit 25 are assigned to “month” (Month[1.0], Month[3.2]), and14 bits from bit 26 to bit 39 are assigned to “year” (Year[5.0],Year[13.6]). A fraction of the picture data recording date/time thatcannot be shown by this format of the VOB_REC_TM is indicated by theVOB_REC_TM_SUB in a unit that is smaller than second and a video frame.

The LOCAL_TM_ZONE will be described later for the case where it isutilized when data is recorded onto the DVD in two or more time zones.

Now, TMAPI will be described. The TMAPI is a table that shows thecorrespondence between VOBU addresses and presentation times. FIG. 7shows the construction of the TMAPI. The TMAPI includes, as the dottedarrow hy3 indicates, TMAP_GI (General Information), TM_ENT (Time ENTry)#1-#S, and VOBU_ENT (VOBU ENTry) #1-#T. Each VOBU_ENT is informationcorresponding to a different VOBU and includes, as the dotted arrow hy4indicates: 1STREF_SZ (firST REFerence SiZe) indicating the size of thefirst I-Picture of the corresponding VOBU; VOBU_PB_TM(VOBU_PlayBack_TiMe) indicating a playback time of the order of 0.4seconds to 1.0 seconds required to play back the corresponding VOBU; andVOBU_SZ (Size) indicating the size of the corresponding VOSU. Even ifthe size or the playback time is different for each VOBU due to theadoption of the variable-length coding, it is possible to access apicture in a VOBU corresponding to any playback time by referring to the“VOBU_ENT”.

The “TM_ENT” is information that indicates the location of a time entryevery 10 seconds. The “TM_ENT” includes, as the dotted arrow hy5indicates: “VOBU_ENTN” that indicates a VOBU containing the time entry;“TM_DIFF” that indicates an offset time between the start of the VOBUshown in the “VOBU_ENTN” and the time entry; and “VOBU_ADR” thatindicates an offset between the start of the VOB and the start of theVOBU shown in the “VOBU_ENTN”. The “TM_ENT” enables a picture in a VOBUto be accessed at a high speed every 10 seconds.

The “TMAP_GI (TimeMap General Information)” is information that is usedto manage the TMAPI as a whole and includes, as the dotted arrow hy6indicates: “TM_ENT_Ns” that indicates the number of time entries set inthe VOB; “VOBU_ENT_Ns” that indicates the number of VOBU_ENTs containedin the TMAPI; “TM_OFS” that indicates an offset between the start of theVOB and one time entry; and “ADR_OFS” that indicates an offset betweenthe start of “VR_MOVIE.VRO” and the start of the VOB.

FIG. 8 shows the relationship between TMAPI and VOBU. In FIG. 8, theplayback time and the size of each VOBU are indicated by eachcombination of a VOBU_PB_TM (represented as “PB_TM” in FIG. 8) and aVOBU_SZ. The “TM_DIFF” in TM_ENT indicates a time differential betweenthe start of the VOBU and the start of the time entry. With the TMAPI ofthe above construction, it is possible to identify a VOBU correspondingto a given time code.

When a relative time Tx from the start of the VOB is specified for apicture to be played back, values for “x”, “y”, “z” satisfying thefollowing Formula 1 are obtained from FIG. 8, the obtained values for xand y are substituted into the following Formula 2 to obtain an addressof VOBU #i corresponding to the relative time Tx, the VOBU #i is readfrom the obtained address on the DVD, and a picture at a location aftera time “z” from the playback start time of the VOBU #i is played back asthe picture for the specified relative time Tx.Relative time Tx for specified picture=10 seconds×x−TM_DIFF for (TM_ENT#x+1)+TM_OFS+ΣVOBU_PB_TM+z  Formula 1In the above formula, ΣVOBU_PB_TM represents a total sum of the firstVOBU_PB_TM to the y^(th) VOBU_PB_TM.Address of VOBU #i=ADR_OFS+VOBU_ADR for (TM_ENT #x+1)+ΣVOBU_SZ  Formula2In the above formula, ΣVOBU_SZ represents a total sum of the firstVOBU_SZ to the y^(th) VOBU_SZ.

Even when a specified picture is accessed using the TMPI and playedback, the recording date/time shown in FIG. 5B is displayed. In thiscase, the recording date/time of the specified picture is obtained byadding the relative time Tx to the VOB_REC_TM of the VOB.

Up to now, “M_AVFIT” has been described. From now on, the other tablesof VR_MANGR.IFO will be described with reference to FIG. 9. FIG. 9 showsthe internal structure of VR_MANGR.IFO. FIG. 9 differs from FIG. 3 inthat it shows the internal structure of the ORG_PGCI table.

The ORG_PGCI (Original Program Chain Information) table is used manage aplurality of VOBs recorded on a DVD so that the VOBs can be played backas in a reel of video tape. More specifically, the ORG_PGCI tablearranges the plurality of VOBs recorded in a DVD to be connected inseries in a playback order called “Original Program Chain”. With thisarrangement, users can regard the DVD as a reel of video tape. In thisarrangement, VOB_REC_TM in each VOBI is referred to and VOBs arearranged in order of time shown in VOB_REC_TM. Here, the relationshipsbetween ORG_PGCI and VOB will be described. The VOBs belong to a logicalhierarchy “PG-CELL-VOB”. The ORG_PGCI is the PGs (programs) in thehighest hierarchy level that have been arranged into a series. TheORG_PGCI table (ORG_PGCIT) is defined so that the logical hierarchy“PG-CELL-VOB” can be achieved. As indicated by the dotted arrow h6 inFIG. 9, the ORG_PGCIT is composed of: ORG_PGCI_EA (Effective Address)showing the effective length of the ORG_PGCI table; PG_Ns showing thenumber of PGs connected in series in the ORG_PGC; CI_SRP_Ns showing thenumber of search pointers corresponding to CELLI (CI); ORG_PGI #1 . . .ORG_PGI #M which are information corresponding to the plurality of PGscontained in ORG_PGC; ORG_CI_SRP #1 . . . ORG_CI_SRP #N which are searchpointers corresponding to the plurality of CELLIs; and ORG_CELLI #1 . .. ORG_CELLI #N.

The ORG_CELLI is information that indicates a logical playback sectionby a combination of time codes, and as the dotted arrow h8 indicates, iscomposed of: VOBI_SRPN being a pointer that points to one among theplurality of VOBIs contained in the M_AVFIT that corresponds to theCELLI, as indicated by the arrow gj1; and CELL_Start_PTM andCELL_End_PTM that are time codes as a pair specifying a section in theVOB as a playback section (referred to as CELL).

FIG. 10 shows relationships between CELLs and VOBs contained inORG_PGCI. As shown in FIG. 10, correspondence between each CELL and eachVOBI is indicated by VOBI_SRPN. A given section constituting a VOB isspecified as a CELL by two VOBU addresses which are obtained as a resultof conversion, through the TMAPI, from a pair of CELL_Start_PTM (C_S_PTMin FIG. 10) and CELL_End_PTM (C_E_PTM in FIG. 10) contained in the CELL.

The ORG_PGI (Original Program Information) is composed of, as the dottedarrow h7 indicates: IT_TXT_SRPN specifying one of a plurality of piecesof text data contained in TXTDT_MG that corresponds to the PG; and CNsindicating the number of CELLIs contained in the PG.

FIG. 11 shows how the CELLs shown in FIG. 9 are assigned to PGs. Asshown in FIG.11, the CNs contained in the PGI indicates the portions ofCELL #1 through CELL #2 that are contained in PG #1 and PG #2,respectively. Furthermore, the IT_TXT_SRPN contained in the PG indicatesthe text data corresponding to the PG.

Up to now, the ORG_PGCI has been described. From now on, the internalstructure of the other tables will be described with reference to FIG.12.

The UD_PGCIT (User-Defined Program Chain Table) is a table that definescombinations of playback sections (referred to as PlayList) set by usersat will.

The TXTDT_MGT (Text Data Manager Table) contains a plurality of piecesof text data defined by users at will, such as broadcast program names,scene names or the like.

The MNFI table is a table in which information unique to each maker ofrecording apparatuses is written.

The RTR_V_TM_MGIT (Real Time Recording Video Management GeneralInformation Table) includes, as the dotted line h20 indicates, VMGI_MAT(Video Management General Information Map Table). The VMGI_MAT iscomposed of, as the dotted arrow h21 indicates: RTR_VMGI_EA being aneffective length of the RTR_VMGIT; and M_AVFIT_SA, ORG_PGCI_SA,UD_PGCI_SA, TXTDT_MG_SA, MNFI_SA, and TM_ZONE.

FIG. 13 shows how areas in the management file assigned to themanagement tables are specified by the start addresses (M_AVFIT_SAthrough MNFIT_SA) written in the VMGI_MAT and the effective lengths(M_AVFIT_EA through MNFIT_EA) written in the management tables. The sign“{” shown on the right-hand side of FIG. 13 indicates the areas in themanagement file assigned to the management tables that are identified byM_AVFIT_SA through MNFIT_SA and M_AVFIT_EA through MNFIT_EA.

The start addresses (M_AVFIT_SA through MNFIT_SA) of the managementtables written in the VMGI_MAT are actually offsets between the start ofVR_MANGR.IFO and the management tables. The M_AVFIT_EA through MNFIT_EAare effective lengths of the management tables. As a result, the endaddresses of the management tables are obtained by adding the startaddresses written in the VMGI_MAT of RTR_VMGI to the effective lengthswritten in the management tables.

Now, TM_ZONE will be described. The TM_ZONE indicates a time zone thatis used as a standard time zone for recording date/time information suchas VOB_REC_TM onto the DVD. Whenever date/time information is recordedin any table in the management file VR_MANGR.IFO, the time zoneindicated by the TM_ZONE must be used as the standard time zone. Thespecification of the time zone by the TM_ZONE is effective in the entireDVD. As a result, the TM_ZONE is sometimes referred to as “volumeoffset”. The VOB_REC_TM for each VOB is also based on the time zonespecified by the TM_ZONE. Therefore, the display of the recordingdate/time shown in FIG. 5 and sorting of VOBs constituting ORG_PGCI areboth based on the time zone specified by the TM_ZONE.

The standard time is divided into (1) Greenwich Mean Time which is theuniversal time, and (2) standard times for different regions. TheTM_ZONE has a format that can conform to any of the above standard timeson which the date/time information is based. FIG. 14 shows time zonesfor different regions on the earth. The longitude lines TK1 to TK5 inFIG. 14 are demarcations between time zones. The time zone shavedifferent standard times that are mean solar times based on theGreenwich Mean Time of the United Kingdom (UK1 in FIG. 14).

FIG. 15 shows the format of TM_ZONE. As shown in FIG. 15, TM_ZONE has 16bits. Of these, 12 bits of bits 0 to 11 are assigned to TZ_OFFSET, and 4bits of bits 12 to 15 are assigned to TZ_TY. The TZ_TY indicates thatthe date/time information is based on the universal time when it is“0000”, and that the date/time information is based on another standardtime when it is “0001”. When the TZ_TY is set to “0001”, the TZ_OFFSETindicates a time differential between the Greenwich Mean Time and thestandard time of the time zone in units of minutes.

FIGS. 16A, 16B, and 16C show in what timing TM_ZONE is referred to andhow VOB_REC_TM is set by the recording apparatus 1 a in Japan. Since therecording apparatus 1 a is in Japan, the timer of the recordingapparatus 1 a measures the current time based on the Japanese StandardTime. The Device_Offset has a time differential from which the standardtime (and the time zone) which the timer of the recording apparatus isbased on can be identified. The Device_Offset is different fromTZ_OFFSET contained in DVDs. As shown in FIG. 16B, the recordingapparatus 1 a is attempting to write a new VOB (i.e. VOB #3) andcorresponding VOBI #3 onto a DVD, and as a result of a judgment, it isjudged that TZ_OFFSET in TM_ZONE matches the Device_Offset in therecording apparatus 1 a, as indicated by the arrow it1. This leads tothe setting of VOBI #3 shown in FIG. 16C. As indicated by the arrow ii1,VOB_REC_TM of VOBI #3 is set to the current time measured by the timerof the recording apparatus 1 a, and as indicated by the arrow ii2,LOCAL_TM_ZONE is set to “0000 0000 0000”.

In the above DVD, all date/time information including VOB_REC_TM isbased on TZ_OFFSET in TM_ZONE, which means all kinds of date/timeinformation are unified.

In the description so far, it was supposed that the DVD is used in thesame time zone as the recording apparatus. The following will describethe case where the DVD is used in a different time zone and in whatformats a recording apparatus records the VOBs and VOBIs in the timezone. In the sample case, it is supposed that the DVD that has been usedin Japan is taken to U.S.A. by the user. FIG. 17 shows a transfer fromJapan to U.S.A., the transfer being indicated by the arrow ty1. Supposethat in U.S.A, the user uses a recording apparatus 1 b that is based ona standard time in U.S.A. In this case, when a new VOB is to be recordedonto the DVD, the date/time information in the new VOB may be based onTM_ZONE of the DVD or the standard time of the recording apparatus 1 b.In the present embodiment, the date/time information in the new VOB isbased on TM_ZONE of the DVD. In addition, LOCAL_TM_ZONE in VOBI is setto Device_Offset in the recording apparatus 1 b.

Here, the LOCAL_TM_ZONE in VOBI will be described. The LOCAL_TM_ZONEbecomes effective when a VOB is recorded in a time zone that isdifferent from the time zone specified by TM_ZONE. The LOCAL_TM_ZONEspecifies the different time zone as a local time zone unique to theVOB. FIG. 18 shows the format of LOCAL_TM_ZONE. As shown in FIG. 18,LOCAL_TM_ZONE has 16 bits. Of these, 12 bits of bits 0 to 11 areassigned to LOCAL_TZ, and 4 bits of bits 12 to 15 are assigned toLOCAL_TZ_TY. The LOCAL_TZ_TY indicates, when it is set to “0000”, thatit does not specify a local time zone, and that the time zone specifiedin TM_ZONE is used. That is to say, “0000” in the LOCAL_TZ_TY indicatesthat the VOB corresponding to the VOBI has been written by a recordingapparatus having a timer that is based on the time zone specified by theTM_ZONE.

The LOCAL_TZ_TY indicates, when it is set to “0001”, that it specifies alocal time zone unique to the VOB. That is to say, “0001” in theLOCAL_TZ_TY indicates that the VOB corresponding to the VOBI has beenwritten by a recording apparatus having a timer that is based on a timezone different from that specified in TM_ZONE. When LOCAL_TZ_TY is setto“0001”, LOCAL_TZ contains a “local offset” that is a time differentialbetween the Greenwich Mean Time and the standard time of the local zone,represented in units of minutes.

The following will describe how the recording apparatus 1 b in U.S.A.writes a new VOB onto the DVD that has the format shown in FIGS. 16A to16C. FIGS. 19A, 19B, and 19C show how the recording apparatus 1 b inU.S.A. sets VOB_REC_TM and TM_ZONE. Since the recording apparatus 1 b isin U.S.A., the Device_Offset of the recording apparatus 1 b indicates astandard time of a time zone in U.S.A. as shown in FIG. 19A. On theother hand, the TM_ZONE is set to the Japanese standard time, as is thecase with FIGS. 16A to 16C. As shown in FIG. 19B, the recordingapparatus 1 b is attempting to write a new VOB (i.e. VOB #3) andcorresponding VOBI #3 onto the DVD, and as a result of a judgment, it isjudged that TZ_OFFSET in TM_ZONE does not match the Device_Offset in therecording apparatus 1 b, as indicated by the arrow it2. This leads tothe setting of VOBI #3 shown in FIG. 19C. As indicated by the dottedarrow tt2, LOCAL_TZ_TY in LOCAL_TM_ZONE is set to “0001”, and LOCAL_TZis set to the Device_Offset of the recording apparatus 1 b.

As indicated by the dotted arrow tt1, VOB_REC_TM is obtained by acalculation: current date/time−LOCAL_TZ+TM_ZONE. In this calculation,the “current date/time” is based on the standard time of the time zonespecified in the LOCAL_TM_ZONE. First, a date/time in the Greenwich MeanTime is obtained by subtracting a time differential shown in theLOCAL_TZ from the “current date/time”. Then, VOB_REC_TM is obtained byadding TM_ZONE to the obtained date/time in the Greenwich Mean Time.This indicates that VOB_REC_TM is based on TZ_OFFSET in TM_ZONE.

This will be considered using an example in which TM_ZONE is written as“+540(=9.0 H)”, and the VOB_REC_TM is to be set to a current date/time“Jan. 11, 2001, 21 (hour): 30 (minutes)” in a time zone having a timedifferential “−2.0 H” from the Greenwich Mean Time. In this case, theLOCAL_TZ in the above formula has a time differential “−120(=−2.0 H)”.First, a date/time in the Greenwich Mean Time is obtained by subtractingthe LOCAL_TZ (−2.0 H) from the “current date/time”. Then, VOB_REC_TM isobtained by adding TM_ZONE (+9.0 H) to the obtained date/time in theGreenwich Mean Time (“Jan. 11, 2001, 23 (hour): 30 (minutes)”). As aconsequence, VOB_REC_TM is set to “Jan. 12, 2001, 8 (hour): 30(minutes)”.

If the VOB_REC_TM is desired to be represented by the standard time ofthe time zone specified in the LOCAL_TM_ZONE, the recording date/time tobe displayed is obtained by the following formula:recording date/time=VOB_REC_TM−TM_ZONE+LOCAL_TM_ZONE

In this case, the date/time in VOB_REC_TM is based on the standard timeof the time zone indicated by TM_ZONE. First, therefore, a date/time inthe Greenwich Mean Time is obtained by subtracting a time differentialshown in the TM_ZONE from VOB_REC_TM. Then, the recording date/time bythe local standard time is obtained by adding a time differential shownin LOCAL_TM_ZONE to the above result.

This will be considered using an example in which TM_ZONE in aVR_MANGR.IFO is written as “+540 (=9.0 H)” and the VR_MANGR.IFO containsan M_VOB_GI that contains LOCAL_TM_ZONE written as “−120 (=−2.0 H)” andVOB_REC_TM written as “Jan. 12, 2001, 8 (hour): 30 (minutes)”. First, adate/time in the Greenwich Mean Time is obtained by subtracting a timedifferential (9.0 H) shown in the TM_ZONE from VOB_REC_TM (Jan. 12,2001, 8 (hour): 30 (minutes)). Then, a time differential (−2.0 H) shownin LOCAL_TM_ZONE is added to the above result. As a consequence, “Jan.11, 2001, 21 (hour): 30 (minutes)” is obtained as the recordingdate/time by the local standard time.

As described above, the present embodiment secures that VOB_REC_TM isset based on TZ_OFFSET specified in TM_ZONE, regardless of the time zonein which the VOB is recorded. More specifically, if a VOB is recorded ona DVD by a recording apparatus that is based on a standard timedifferent from that defined for the DVD, VOB_REC_TM is set based onTZ_OFFSET specified in TM_ZONE. This means that all date/timeinformation written in VOB_REC_TMs are unified, namely based onTZ_OFFSET specified in TM_ZONE. This provides an effect that even ifVOBs, which have been recorded by various recording apparatuses based ondifferent standard times, are sorted in the order of recording date/timeinto one ORG_PGCI, VOBs are always properly arranged. The presentembodiment provides another effect that the recording date/time can bedisplayed by the local time by converting standard times using LOCAL_TZin LOCAL_TM_ZONE, not by the recording date/time shown in VOB_REC_TM.This allows the user to feel normal when he/she views the played backimages and the displayed recording date/time together.

Embodiment 2

Embodiment 2 discloses a recording apparatus 1 of a camcorder type forachieving the DVD shown in Embodiment 1. FIG. 20 shows the internalstructure of the recording apparatus 1 in Embodiment 2. As shown in FIG.20, the recording apparatus 1 includes a user interface unit 2, a timer3, a capturing unit 4, an MPEG encoder 5, a track buffer 6, a driveapparatus 7, a writing unit 8, a semiconductor memory 9, a systemcontrol unit 10, a recording control unit 11, and a date/timeinformation setting unit 12.

The user interface unit 2 receives various inputs from the user via apanel, a remote controller, a display or the like. The inputs receivedby the user interface unit 2 in Embodiment 2 includes a specification ofa country, a recording start instruction, and a recording endinstruction.

The timer 3 measures the current time. The current time measured by thetimer 3 is based on the standard time of the country in which therecording apparatus 1 is used. It should be noted here that in thepresent document, for the sake of convenience, it is presumed that onecountry has one standard time. The timer 3 holds, in correspondence witha plurality of countries, a plurality of time differentials from whichstandard times can be identified. The timer 3 determines a timedifferential corresponding to a country specified by an input that theuser interface unit 2 receives from the user. This enables the user tochange the standard time on which the recording apparatus 1 is basedwhen the user goes to a different country with the recording apparatus1.

The capturing unit 4 includes a lens, an iris diaphragm, an image pickupdevice for receiving incoming light, and an amplifying circuit foramplifying an output of the image pickup device and outputting theamplified out come. The capturing unit 4 outputs video signals and audiosignals. Each video signal is composed of a plurality of video frames,and each audio signal is composed of a plurality of audio frames. Thecapturing unit 4 sequentially outputs the video and audio frames to theMPEG encoder 5.

The MPEG encoder 5 generates picture data by video-encoding the videoframes input from the capturing unit 4, and at the same time generatesaudio data by audio-encoding the audio frames input from the capturingunit 4.

The MPEG encoder 5 interleave-multiplexes the generated picture data andaudio data into VOBUs, and sequentially stores the VOBUs in the trackbuffer 6. Every time it completes system encoding of VOBUs, the MPEGencoder 5 notifies the system control unit 10 of information on theVOBUs (VOBU information). The VOBU information is divided into thefollowing information:

-   VOBU Start PTM (a time to start playing back video frames of a VOBU)-   Reference Picture Size (a size of the first I-Picture of a VOBU,    where the VOBU start is regarded as “0”)-   VOBU_Size (a size of a VOBU)-   VOBU_PB_Time (a playback time of a VOBU)

The above information are used to create VOBU_ENT in TMPI. Whenever thesystem control unit 10 receives such VOBU information from the MPEGencoder 5, it creates VOBU_ENT using the received information.

The drive apparatus 7 accesses a DVD and includes a base on which theDVD is set, a spindle motor for clamping the set DVD and driving the DVDfor rotation, an optical pickup for reading out signals recorded on theDVD, and an actuator for the optical pickup. The drive apparatus 7contains the writing unit 8.

The writing unit 8 records VOBUs stored in the track buffer 6 onto a DVDeach time the track buffer 6 is filled with VOBUs encoded by the MPEGencoder 5.

The semiconductor memory 9 is a storage area for storing the managementfile “VR_MANGR.IFO” as a resident file, where the file “VR_MANGR.IFO” isto be recorded onto a DVD set on the recording apparatus 1. Themanagement file “VR_MANGR.IFO” is allowed to stay resident in thesemiconductor memory 9 to avoid a conflict between a disc access forrecording a VOBU and a disc access for updating the management file.

The system control unit 10 includes a CPU, a main storage, and a ROM,and also includes the recording control unit 11 and the date/timeinformation setting unit 12.

The recording control unit 11 sets parameters, which are received by theuser interface unit 2 at the recording start, into the MPEG encoder 5,where the parameters relate to a video compression method, a system bitrate or the like. The recording control unit 11 also creates prototypesfor VOB STI, VOBI, and CellI in VR_MANGR.IFO, and requests the MPEGencoder 5 to encode video and audio frames. Each time a system encodingof a VOBU is completed, the recording control unit 11 receives the VOBUinformation from the MPEG encoder 5, and updates VR_MANGR.IFO inaccordance with the received VOBU information. After receiving arecording end instruction input by the user and being informed ofcompletion of an encoding from the MPEG encoder 5, the recording controlunit 11 records all the VOBUs and the management file stored in thetrack buffer 6 onto the DVD via the drive apparatus 7, and ends therecording process.

The date/time information setting unit 12 sets VOB_REC_TM andLOCAL_TM_ZONE in VOBIs when a VOB is recorded. Now, the procedure of theoperation performed by the date/time information setting unit 12 will bedescribed with reference to the flowchart shown in FIG. 21. Theflowchart focuses on how VOB_REC_TM and LOCAL_TM_ZONE are set. Thesetting has three patterns: steps S4–S5, steps S7–S8, and steps S9–S10.In the procedure, one of the setting patterns is selected in accordancewith the results of judgments performed in steps S3 and S6.

The MPEG encoder 5 and the drive apparatus 7 are instructed to record aVOB onto a DVD (step S1). The TM_ZONE in VMGI_MAT in RTR_VMGI isreferred to (step S2). It is judged whether TZ_TY in TM_ZONE is “0000”or “0001” (step S3). When TZ_TY is “0000”, steps S4 and S5 areperformed. The fact that TZ_TY is “0000”indicates that the date/timeinformation in the DVD is based on the universal time.

The LOCAL_TM_ZONE in a VOBI is set to “0” (that is to say, all bits areset to 0) (step S4). The VOB_REC_TIME by the universal time iscalculated by subtracting Device_Offset from the current time measuredby the timer 3 (step S5).

Step S6 is performed only when it is judged in step S3 that TZ_TY inTM_ZONE is “0001”. The fact that TZ_TY is “0001” indicates that thedate/time information in the DVD is based on a standard time for a timezone other than the universal time. In this case, it matters whether therecording apparatus 1 and the DVD are based on the same standard time.This is judged in step S6. That is to say, in step S6, the value ofTZ_OFFSET in TM_ZONE in RTR_VMGI in the DVD is compared with the valueof Device_Offset in the timer 3 to judge whether they match. When theymatch, the LOCAL_TM_ZONE in the VOBI is set to “0” (step S7). TheVOB_REC_TIME is set to the current time measured by the timer 3 (stepS8). When it is judged that the TZ_OFFSET does not match theDevice_Offset in step S6, the LOCAL_TZ is set to the Device_Offset, andLOCAL_TM_ZONE containing the LOCAL_TZ and LOCAL_TZ_TY set to “0001” arewritten into the VOBI (step S9). The VOB_REC_TM is obtained byperforming the calculation: “(current time of timer3)−LOCAL_TZ+TZ_OFFSET” (step S10).

The VOB_REC_TM and LOCAL_TM_ZONE have been set in the above steps.Completion of a VOB encoding is waited (step S11). After it is judged instep S11 that the VOB encoding is completed, the VOBI stored in thesemiconductor memory 9 is written onto the DVD (step S12).

As described above, according to the present embodiment, a conventionalrecording apparatus 1 can set the VOB_REC_TM and LOCAL_TM_ZONE togenerate the DVD described in Embodiment 1. It is expected thereforethat the present embodiment will enhance wider use of the DVD ofEmbodiment 1.

Here, the following should be noted. In the present embodiment, whenTZ_TY in TM_ZONE is “0000” (indicating that the date/time in DVD isbased on the universal time), LOCAL_TM_ZONE is also set to “0” (allzero). However, if TZ_TY in TM_ZONE is “0000”, LOCAL_TM_ZONE may be setto a value indicating a standard time for a time zone in which therecording apparatus is used. To achieve this setting, the judgment instep S3 is omitted, and it is judged in step S6 whether TZ_OFFSETmatches Device_Offset. If it is judged in step S6 that TZ_OFFSET doesnot match Device_Offset, LOCAL_TM_ZONE is set to Device_Offset, andTZ_OFFSET set to “0” is applied to step S10 to obtain VOB_REC_TM.

Embodiment 3

Embodiment 3 relates to a playback apparatus for playing back the DVDdisclosed in Embodiment 1. FIG. 22 shows the internal structure of theplayback apparatus in Embodiment 3. As understood from FIG. 22, theinternal structure of the playback apparatus is based on that of therecording apparatus 1 in Embodiment 2. As a result, the playbackapparatus in Embodiment 3 has functions of both the recording andplayback apparatuses. As shown in FIG. 22, the playback apparatusincludes an MPEG decoder 13, a reading unit 14, a play back control unit15, a display mode storage unit 16, a country mark storage unit 17, aplayback time monitoring unit 18, a signal combining unit 19, and adate/time display control unit 20 in addition to the components of therecording apparatus 1 shown in FIG. 20. The components having the samereference numbers as those of the recording apparatus 1 are notdescribed in detail here since they have the same functions. Thefollowing description focuses on the newly added components.

The MPEG decoder 13, when receiving a decoding request from the playbackcontrol unit 15, decodes a VOBU, which has been read from a DVD andstored in the track buffer 6, to obtain a video signal, and outputs theobtained video signal to the signal combining unit 19.

The reading unit 14 is contained in the system control unit 10 inEmbodiment 3. When the DVD is played back, the reading unit 14 accessesthe DVD and reads VOBUs from the DVD and sequentially stores the readVOBUs into the track buffer 6. The reading and storing of VOBUs iscontinued until the track buffer 6 is filled with VOBUs. After the trackbuffer 6 is filled with VOBUs, the reading unit 14 waits until a freespace is generated in the track buffer 6. After a free space isgenerated, the reading unit 14 newly reads out data from the DVD andwrites the data into the track buffer 6, taking care on under flow.

The playback control unit 15 refers to pieces of CELL information inORG_PGCI one by one, obtains the address and size of each VOBU fromCELL_Start_PTM and CELL_End_PTM written in the read pieces of CELLinformation, instructs the drive apparatus to read the identified VOBUsfrom the DVD one by one, and instructs the MPEG decoder 13 to decode theVOBUs so that the VOBUs corresponding to the ranges specified byCELL_Start_PTM and CELL_End_PTM are played back.

The display mode storage unit 16 stores a display mode in which therecording date/time is displayed. In the present embodiment, two displaymodes are provided: recording place time mode; and playback place timemode. As described in Embodiments 1–3, the date/time information isbased on the standard time of the time zone specified by either (a)TZ_OFFSET in TM_ZONE or (b) LOCAL_TZ in LOCAL_TM_ZONE. When therecording place time mode is selected by the user, the display modestorage unit 16 is set to the recording place time mode, and thedate/time information based on either (a) or (b) above is used. However,the user may take the playback apparatus into a time zone that isneither the time zone identified by TM_ZONE nor the time zone identifiedby LOCAL_TM_ZONE. This may happen quite often since use of portableplayback apparatuses has become widespread recently. In this case theuser can select the playback place time mode to play back a VOB. Withthis selection, the display mode storage unit 16 is set to the playbackplace time mode. FIG. 23A shows a menu screen on which the user canselect either the recording place time mode or the playback place timemode via the user interface unit 2. The user selects one of the buttonsbn1 and bn2 that correspond to the recording place time mode and theplayback place time mode, respectively.

The country mark storage unit 17 stores a plurality of time differentialvalues that are set to either TZ_OFFSET or LOCAL_TZ, and also stores acorresponding plurality of marks that indicate countries including theUK with the universal time. FIG. 23B shows the information stored in thecountry mark storage unit 17. As shown in FIG. 23B, the value “0.0H”corresponds to the mark indicating the UK providing the universal time;the value “9.0H” indicating the time differential between the universaltime and the Japanese standard time corresponds to the mark indicatingJapan; and the value “−8.0H” indicating the time differential betweenthe universal time and the U.S.A. standard time corresponds to the markindicating U.S.A.

The playback time monitoring unit 18, after a playback of a VOB isstarted, monitors the playback elapse time. More specifically, everytime a piece of picture data to be displayed changes, the playback timemonitoring unit 18 adds the playback elapse time up to the precedingpiece of picture data to the displayed recording date/time of the firstpiece of picture data of the VOB, so that the sum can be displayed asthe recording date/time of the new piece of picture data.

The signal combining unit 19 obtains a composite video signal bysuperimposing (a) a mark stored in the country mark storage unit 17 and(b) a character sequence representing a date/time for a piece of picturedata obtained by the playback time monitoring unit 18 onto the imagecorresponding to the piece of picture data.

The date/time display control unit 20 calculates a recording date/timeto be superimposed on a playback image corresponding to picture data,and selects a mark to be displayed together with the recordingdate/time. Now, the procedure of the operation performed by thedate/time display control unit will be described with reference to theflowchart shown in FIG. 24. The flowchart focuses on how the recordingdate/time to be superimposed on the playback image is calculated, andhow the mark to be displayed together with the recording date/time isselected. This process includes three patterns: steps S23–S24, stepsS26–S27, and steps S28–S31. In the procedure, one of the settingpatterns is selected in accordance with the results of judgmentsperformed in steps S22–S25.

The drive apparatus 7 and the MPEG decoder 13 are instructed to playback a VOB (step S21). It is judged whether the display mode stored inthe display mode storage unit 16 is the recording place time mode or theplayback place time mode. When it is judged that the playback place timemode is stored, the control goes to step S23 in which the recordingdate/time is obtained by performing a calculation“VOB_REC_TM−TZ_OFFSET+Device_Offset”. A mark indicating the countrycorresponding to the Device_Offset is then selected from the countrymark storage unit 17 (step S24). When it is judged that the recordingplace time mode is stored, the control goes to step S25 in which it isjudged whether LOCAL TZ TY in LOCAL TM ZONE is “0000” or “0001”. WhenLOCAL_TZ_TY is “0000”, the control goes to step S28. The fact thatLOCAL_TZ_TY is “0000” indicates that VOB_REC_TM is based on theuniversal time or the standard time specified by TZ_OFFSET in TM_ZONE.In step S28, the date/time shown in VOB_REC_TM is displayed as it is. Itis then judged whether TZ_TY in TM_ZONE is “0000” or “0001” (step S29).When TZ_TY is “0000”, the mark indicating the universal time is selected(step S30). When TZ_TY is “0001”, a mark corresponding to the countryspecified by TZ_OFFSET in TM_ZONE is selected (step S31).

When it is judged in step S25 that LOCAL_TZ_TY is “0001”, the controlgoes to step S26. The fact that LOCAL_TZ_TY is “0001” indicates thatLOCAL_TZ in LOCAL_TM_ZONE is set to an effective value. In step S26, therecording date/time is obtained by performing a calculation“VOB_REC_TM−TZ_OFFSET+LOCAL_TZ”. A mark indicating the countrycorresponding to TZ_OFFSET in TM_ZONE is then selected from the countrymark storage unit 17 (step S27).

After a recording date/time and a mark are determined in one of theabove three patterns, the control goes to step S32 in which the signalcombining unit 19 is instructed to obtain a composite video signal bysuperimposing the obtained mark and recording date/time onto the imageof the first piece of picture data in the VOB, and output the compositevideo signal. It is judged in step S33 whether the next piece of picturedata has been displayed. When it is judged that the next piece ofpicture data has been displayed, the control goes to step S34 in whichthe playback elapse time is obtained from the playback time monitoringunit 18, and a recording date/time after one frame is generated byadding the playback elapse time to VOB_REC_TM , and the signal combiningunit 19 is instructed to obtain and output a composite video signal bysuperimposing the mark and recording date/time onto the image of thedisplayed image. FIG. 25 shows an example of the screen displayed by theabove procedure, the screen containing an image on which a recordingdate/time and a mark obtained by the date/time display control unit 20.Back to the above procedure, in step S35, it is judged whether all VOBUshave been read. The steps S33 to S35 are repeatedly performed while thedrive apparatus 7 continues to read VOBUs. After the VOBU readingcompletes, it is judged in step S35 that all VOBUs have been read, andthe process of the present flowchart ends. As shown in FIG. 25, arecording date/time KH1 and a mark mk1 obtained in one of the threepatterns (steps 23–S24, steps 25–S27, and steps 28–S31) by the date/timedisplay control unit 20 are superimposed on a playback image gz1 ofpicture data in the VOB.

As described above, the present embodiment enables a conventionalplayback apparatus to display a recording date/time based onLOCAL_TM_ZONE. This increases the chances of using the DVD disclosed inEmbodiment 1.

Embodiment 4

Embodiment 4 relates to a playback apparatus that displays a list ofrecorded contents when three VOBs are recorded onto one DVD in threedifferent time zones.

The following describes how VOB REC TM and LOCAL TM ZONE are set whenthree VOBs are recorded onto one DVD in three different time zones suchas Japan, UK, and U.S.A. FIG. 26 shows three VOBs recorded in threedifferent time zones: Japan, UK, and U.S.A. FIG. 26 indicates that VOB#1 was recorded in Japan at 12;00.00 on November 5 (indicated by thearrow kh1) by Japanese standard time; VOB #2 was recorded in the UK at13:30.00 on November 5 (indicated by the arrow kh2) by the universaltime; and VOB #3 was recorded in U.S.A. at 13:00.00 on November 5(indicated by the arrow kh3) by the U.S.A. standard time. Judged fromonly these recording date/times, it appears that VOB #3 was recordedearlier than VOB #2 and that they are sorted into “VOB #1-VOB #3-VOB #2”in the time order. It is supposed here that the three VOBs are recordedonto a DVD 100 which is based on the Japanese standard time. In thiscase, in TM_ZONE of the DVD 100, TZ_TY is set to “0001”, and TZ_OFFSETis set to “+9.0H” that is a time differential indicating the Japanesestandard time. For VOB#1, VOB_REC_TM in the DVD 100 is set to therecording date/time kh1 since it is represented by the Japanese standardtime. In the case of VOB #3 recorded in U.S.A., a date/time to whichVOB_REC_TM should be set is obtained by a calculation “(11/5 13:00.00)kh3−(−8.0H)+9.0H”, which equals to “11/6 6:00.00” vr3. Similarly, in thecase of VOB #2 recorded in the UK, a date/time to which VOB_REC_TMshould be set is obtained by a calculation “(11/513:30.00)kh2−(0.0H)+9.0H”, which equals to “11/5 22:30.00” vr2.

FIG. 27 shows VOBI that contains the VOB_REC_TMs obtained from FIG. 26.The VOBI is divided into three playback units composed of verticalsequences: “VOB #1-VOBI #1-CELL #1-PG #1”; “VOB #2-VOBI #2-CELL #2-PG#2”; and “VOB #3-VOBI #3-CELL #3-PG #3”. The playback units arearranged, from left to right, in the order of actual recordingdate/time. In LOCAL_TM_ZONE of VOB #3 recorded in U.S.A., LOCAL_TZ isset to “−8.0H” and LOCAL_TZ_TY is set to “0001”. In LOCAL_TM_ZONE ofVOB#2 recorded in the UK, LOCAL_TZ is set to “0.0H” and LOCAL_TZ_TY isset to “0001”. This is because these time zones are different from thetime zone (Japan) identified from TM_ZONE of the DVD 100. The ORG_PGCIis composed of PG #1-PG #3 in the order shown in FIG. 27, where PG #1-PG#3 correspond to VOB #1-VOB #3, respectively. As a result, when the DVDis played back, the three VOBs recorded in the three countries areplayed back in the order of the time written in VOB_REC_TM. Up to now,setting of VOB_REC_TM has been described. From now on, the playbackapparatus that performs a “volume display” of the DVD 100 will bedescribed.

FIG. 28 shows the internal structure of the playback apparatus inEmbodiment 4. The playback apparatus additionally contains a volumedisplay executing unit 21, in comparison with the playback apparatus ofEmbodiment 3.

The volume display executing unit 21 executes a “volume display” whenthe DVD is inserted into the playback apparatus. Note that in thepresent embodiment, the “volume display” refers to a sequential displayof VOB-VOBI-CELL-PG that constitute ORG_PGCI. FIG. 29 shows an exampleof the volume display generated by the volume display executing unit 21.In FIG. 29, the graphic images gk1, gk2, and gk3 are OSD (On ScreenDisplay) graphic images that represent sets of VOB-VOBI-CELL-PG,respectively. The graphic images contain text data tx1, tx2, and tx3specified by IT_TXT_SRP in PGI, capturing times kh1, kh2, and kh3, andmarks mk1, mk2, and mk3 indicating the capturing places (countries),respectively.

The capturing time of VOB #1, for which LOCAL_TZ_TY is set to “0000”, isthe same as the time set to VOB_REC_TM. In contrast, the capturing timesof VOBs #2 and #3, for which LOCAL_TZ_TY is set to “0001”, are theresults of a calculation “VOB_REC_TM−TZ_OFFSET+LOCAL_TZ”.

More specifically, the capturing time of VOB #2 (11/5 13:30) is theresult of a calculation “11/5 22:30 (VOB_REC_TM)+0.0H (LOCAL_TZ)−9.0H(TZ_OFFSET) performed by the volume display executing unit 21. Also, thecapturing time of VOB #3 (11/5 13:00) is the result of a calculation“11/6 6:00 (VOB_REC_TM )+(−8.0H=LOCAL_TZ)−9.0H (TZ_OFFSET) performed bythe volume display executing unit 21. It should be noted here that thesecalculation results are off course the same as “11/5 13:30.00” kh2 and“11/5 13:00.00” kh3 shown in FIG. 26.

The volume display executing unit 21 then selects marks. For a VOB inwhich TZ_TY is set to “0001” and LOCAL_TZ_TY is set to “0000”, thevolume display executing unit 21 selects and displays a mark based onTZ_OFFSET. For a VOB in which TZ_TY is set to “0001” and LOCAL_TZ_TY isset to “0001” (in the present example, VOBs #2 and #3), the volumedisplay executing unit 21 selects and displays a mark corresponding to acountry with a standard time which is different from the universal timeby the value in LOCAL_TZ.

As shown in FIG. 29, the graphic image gk1 has a mark indicating Japansince TZ_OFFSET in the DVD 100 indicates the Japanese standard time, andthe graphic images gk2 and gk3 have marks respectively indicating UK andU.S.A. since LOCAL_TZ of VOBs #2 and #3 indicate the universal time andthe U.S.A. standard time, respectively.

As described above, the present embodiment displays a list of VOBsrecorded on a DVD that have been sorted in the order of the time writtenin VOB_REC_TM. This facilitates the user's arrangement of the contentsof the DVD.

Embodiment 5

Embodiment 4 disclosed displaying of a VOB list in accordance withORG_PGCI. Embodiment 5 relates to displaying of a list of VOBs containedin PlayLists. First, UD_PGCIT will be described in detail with referenceto FIG. 30.

As indicated by a dotted leader line h9 in FIG. 30, the UD_PGCIT(User-Defined Program Chain Table) includes: UD_PGCIT_EA indicating theeffective length of the UD_PGCIT; UD_PGCI_SRP_Ns indicating the numberof UD_PGCI_SRPs; UD_PGCI_SRP#1 . . . #K being search pointers pointingto UD_PGCIs on a one-to-one basis; and UD_PGCI #1. . . #K beinguser-defined PGC information. The UD_PGCI specifies a user-definedplayback order referred to as PlayList (PL). As indicated by a dottedleader line h10 in FIG. 30, each UD_PGCI includes: CELLI_SRP_Nsindicating the number of UD_CI_SRPs; UD_CI_SRP#1 . . . #M being searchpointers pointing to UD_CELLIs (UD_CIs) on a one-to-one basis; andUD_CELLI (User-Defined Cell Information) #1 . . . #M defining playbacksection cells constituting a PL. The CELLI in UD_PGCI has the sameconstruction as CELLI in ORG_PGI. As indicated by a dotted leader lineh11 in FIG. 30, each UD_CELLI includes: VOBI_SRPN being a search pointerpointing to a VOBI in the VOB corresponding to the CELL; CELL_Start_PTMbeing a time code indicating the start point of the CELL; andCELL_End_PTM being a time code indicating the end point of the CELL.

FIG. 31 shows a PL defined in correspondence with the VOBs and TMAPIsshown in FIG. 30. As shown in FIG. 31, VOBI_SRPN for CELL #1 containedin PL#1 points to TMAP #1 contained in VOBI #1. Also, a pair ofCELL_Start_PTM (C_S_PTM in FIG. 31) and CELL_End_PTM (C_E_PTM in FIG.31) indicates a portion of VOB #1 corresponding to CELL #1 contained inPL #1. The IT_TXT_SRFN contained in a PL indicates text datacorresponding to the PL.

The RTR_VMGI in Embodiment 5 contains PL_SRPT (PlayList Search PointerTable) which is used to jump to a PlayList, where it is presumed that nPlayLists are recorded on one DVD.

FIG. 32 shows the internal structure of RTR_VMGI in Embodiment 5. Asindicated by the dotted arrow h31, the PL_SRPT includes n PL_SRPs. Asindicated by the dotted arrow h32, each PL_SRP includes: a reservedarea; PL_TY (PlayList Type) indicating the type of the PlayList which isdivided into three types based on whether the PlayList is composed of(1) only moving pictures, (2) only still pictures, or (3) movingpictures and still pictures; PGCN (PGC Number) being a PGC numbercorresponding to the PlayList; PL_CREATE_TM indicating the year, month,day, hour, minute, and second when the PlayList was defined; PRM_TXTI inwhich text information indicating the contents of the PlayList; andREP_PICTI in which information on an image that is representative of thePlayList is written.

A plurality of PlayLists can be recorded on one DVD, while it is definedthat only one ORG_PGCI can be recorded on one DVD. When a plurality ofPlayLists are recorded on a DVD, there will be a demand for a convenientway to see the contents of the PlayLists at a glance.

Now, the playback apparatus in the present embodiment will be described.FIG. 33 shows the internal structure of the playback apparatus in thepresent embodiment. The playback apparatus in the present embodiment isthe same as that in Embodiment 4 except that it additionally has aPlayList browser 22.

The PlayList browser 22, immediately after a DVD is inserted into theplayback apparatus, displays a list of PlayLists recorded on the DVD.FIG. 34 shows a menu screen displaying a list of the plurality ofPlayLists recorded on the DVD. In FIG. 34, the graphic images gk1, gk2,and gk3 are OSD graphic images that represent the PlayLists recorded onthe DVD. The graphic images contain titles ha1, ha2, and ha3 and editingdate/times pd1, pd2, and pd3, respectively. The editing date/times pd1,pd2, and pd3 are generated from PL_CREATE_TM in PL_SRP. The titles ha1,ha2, and ha3 text data written in PRM_TXTI in PL_SRP. The PlayListbrowser 22 brings one of the graphic images into focus in accordancewith an input via a remote control. At the same time, the PlayListbrowser 22 displays images corresponding to the PlayList in focus. Theimages gz1, gz2, and gz3 are generated from the picture data in the VOBsspecified by the PlayList in focus. As shown in FIG. 34, recordingdate/times kh1, kh2, and kh3 and marks kn1, kn2, and kn3 aresuperimposed on the images gz1, gz2, and gz3, At respectively. Therecording date/times kh1, kh2, and kh3 are generated from VOB_REC_TM forthe VOBs. The marks kn1, kn2, and kn3 indicate the countries in whichthe VOBs were recorded. They give the viewers an at-a-glance picture ofwhen and where the VOBs contained in the PlayList were recorded.

As described above, when a plurality of PlayLists are recorded on a DVD,the present embodiment gives the viewers an at-a-glance picture of whenand where the VOBs contained in the PlayLists were recorded. Thisfacilitates reviewing of editing results.

Note that LOCAL_TM_ZONE unique to PL_CREATE_TM may be provided in thereserved area in PL_SRP. The PL_CREATE_TM is date/time informationindicating the date/time when the PlayList was defined, and is based onthe time zone specified by TZ_OFFSET in TM_ZONE. However, a PlayListedited in a time zone different from that specified by TZ_OFFSET may berecorded on the DVD.

To deal with this, LOCAL_TM_ZONE is set for each PL_SRP.

Embodiment 6

Embodiment 6 relates to how VOB_REC_TM and LOCAL_TM_ZONE should be setfor a VOB when the VOB is edited. FIGS. 35A and 35B show how VOBportions are specified when VOBs are partially deleted. FIG. 35A showsthat two news report images A and B captured in two counties withdifferent time zones are recorded on a DVD as VOBs #1 and #2, asindicated in the fourth row in the figure. The VOBs #1 and #2 aremanaged as cells as indicated in the third row, recorded as PGs asindicated in the second row, and the two PGs are combined to form anORG_PGC indicated in the first row.

It is supposed here that after the VOBs, cells, and PGs of the newsreport images A and B are recorded onto the DVD, the portions pt1, pt2,pt3, and pt4 of VOBs #1 and#2 are specified as portions to be deleted,as indicated by FIG. 35B. After this deletion is completed, the old VOB#1 is divided into three new VOBs #1 to #3, and the old VOB #2 isdivided into three new VOBs #4 to #6, as shown in FIG. 36. This VOBdivision leads to a cell division. That is to say, the old cell #1 isdivided into three new cells #1 to #3, and the old cell #2 is dividedinto three new cells #4 to #6. However, the relation between the cellsand the PGs does not change. For example, the news report image A thatwas managed as PG #1 containing one cell (the old cell #1) and one VOB(the old VOB #1) before the division is managed as PG #1 containingthree cells (the new cells #1–#3) and three VOBs (the new VOBs #1–#3)after the division.

According to the above-described Embodiment 6, even if a VOB is deletedpartially by editing, the management of images is facilitated since PGis used as a unit for managing recorded images.

Now, how VOBI is set after a corresponding VOB is partially deleted.FIGS. 37A and 37B show how VOB_REC_TM and LOCAL_TM_ZONE are set for anew VOB that is created after a middle portion of the old VOB isdeleted. In case the starting portion of a VOB is deleted, VOB_REC_TM isupdated to a time obtained by performing a calculation “time period ofthe deleted portion+former VOB_REC_TM ”. The application of this rule tothe present case results as follows. The VOB_REC_TM of the new VOB #2 isobtained by performing a calculation “VOB_REC_TM of new VOB #1+Length1+Length2”, where Length1 represents a time period between thestart of the new VOB #1 and the start of the deleted middle portion, andLength2 represents a time period of the deleted portion. For example, ifthe old or new VOB #1 was recorded at 12:00:00 on Sep. 2, 2001, and if“Length1+Length2” equals to 1:00:00H, the VOB_REC_TM of VOB#2 is“2001/9/2 13:00:00”. The date/time information in VOB_REC_TM conveystime in units of seconds at the minimum. As a result, if a portion isdeleted in units of video frames or video fields that are more minutethan video frames, the VOB_REC_TM cannot express the starting point ofthe new VOB #2 accurately. To deal with this problem, a fraction of theVOB_REC_TM is written in VOB_REC_TM_SUB in VOBI for the new VOB #2 inunits of video frames or video fields.

When LOCAL_TZ_TY and LOCAL_TZ are set in the VOBI for the old VOB #1,the same LOCAL_TZ_TY and LOCAL_TZ are set in the VOBI for the new VOB#2.

As described above, even if a new VOB is obtained as a result of editinga VOB that was recorded in a time zone different from a time zonespecified by TZ_OFFSET in TM_ZONE, the same LOCAL_TM_ZONE is set to thenew VOB as the old VOB. Accordingly, the present embodiment achieves thesame time management as Embodiment 1.

Embodiment 7

Embodiments 1–6 have dealt with VOBs recorded on a DVD that containmoving-picture data. Embodiment 7, relates to an improvement in the casewhere date/time information is added to VOBs containing still picturedata. FIG. 38 shows the file system for DVDs on which VOBs containingstill picture data (hereinafter referred to as Still_VOBs) are recorded,as well as VOBs containing moving-picture data. The difference betweenthis file system and the file system shown in FIG. 1 is that it containsVR_STILL.VRO. The VR_STILL.VRO is a file that contains Still_VOBs. FIG.39 shows hierarchical representation of Still_VOBs contained in aVR_STILL.VRO. One Still_VOB in FIG. 39 corresponds to one still picture.As shown in the third row of FIG. 39, each Still_VOB is composed of: asequence header; a GOP header; an I-Picture (Intra Picture); a sequenceend code; and a plurality of pieces of Audio data. The sequence end codeis used to suspend the operation of the MPEG decoder. The operation ofthe MPEG decoder contained in a DVD player is suspended immediatelyafter it decodes the sequence end code, and the most recently decodedpicture is kept to be displayed. This provides a playback operation thatmakes the user feel as if the user is leafing through a book page bypage. Note that the Audio data is dispensable for Still_VOBs. This isbecause Still_VOBs may not contain address data or that the address dataof Still_VOBs may be stored as dubbing data in a different file.

The Still_VOG (Video Object Group) shown in the first row of FIG. 39 iscomposed of up to 64 Still_VOBs that have the same image attribute. TheStill_VOG is information unit to which playback control information isassigned. The management file has a construction in which the playbackcontrol information is assigned in units of Still_VOGs.

Now, the internal structure of the management file will be described.FIG. 40 shows the internal structure of the management file inEmbodiment 7. The management file in Embodiment 7 is characterized by anewly added S_AVFI table.

The S_AVFI table, as indicated by the dotted arrow h51, includes:S_VOB_STI #1 . . . #k; and S_AVFI.

The S_VOB_STI #1 . . . #k are stream attribute information thatindicates (a) a video attribute (compression method, aspect ratio,NTSC/PAL, line21 information, etc.) of picture data contained in eachStill_VOB and (b) an audio attribute (compression method, the number ofchannels, frequency, etc.) of audio data contained in each Still_VOB.

The S_AVFI, as indicated by the dotted arrow h52, includes: S_VOGI_SRP(Search Pointer) #1 . . . #n that are search pointers pointing toS_VOGIs on a one-to-one basis; and S_VOGI #1 . . . #n.

The S_VOGI, as indicated by the dotted arrow h53, includes: S_VOG_GIbeing playback control information on Still_VOG; and S_VOB_ENT #1 . . .#m that are entry information on each of the Still_VOBs contained in theStill_VOG.

The S_VOB_ENT is entry information that indicates a type of eachStill_VOB in the Still_VOG, and more specifically, indicates whether theStill_VOB is a still picture without audio, with audio, or with dubbingaudio.

The S_VOG_GI, as indicated by the dotted arrow h54, includes: S_VOB_Nsindicating the number of Still_VOBs contained in the Still_VOG;S_VOB_STIN (Stream Information Number) indicating an S_VOB_STI referredto by the present S_VOGI among the plurality of S_VOB_STINs;FIRST_VOB_REC_TM indicating the date/time when the first Still_VOB inthe Still_VOG was recorded; LAST_VOB_REC_TM indicating the date/timewhen the last Still_VOB in the Still_VOG was recorded; S_VOG_SA (StartAddress) being the starting address of the Still_VOG in the RTR_STO.VROfile; LOCAL_TM_ZONE specifying, as a local zone, a time zone in whichthe Still_VOG was recorded.

The reason why the LOCAL_TM_ZONE is provided in the Still_VOG is asfollows. The FIRST_VOB_REC_TM and the LAST_VOB_REC_TM are date/timeinformation on Still_VOBs contained in the Still_VOG, and are based on atime zone specified by TZ_OFFSET in TM_ZONE. However, a Still_VOGcaptured in a different time zone from that specified by TZ_OFFSET maybe recorded on the DVD. To deal with this, LOCAL_TM_ZONE is set inS_VOG_GI for each Still_VOG.

The ORG_PGCI table in Embodiment 7 differs from that in Embodiment 1 inthat it contains CELL information on the still picture cells.

The still picture cell, as indicated by the dotted arrow h55 in FIG. 41,includes: C_TY indicating that the present cell is a still picture cell;S_VOGI_SRPN specifying, among a plurality of pieces of video objectinformation, one piece that corresponds to the present still picturecell; S_S_VOB_ENTN; and E_S_VOB_ENTN. The S_S_VOB_ENTN and E_S_VOB_ENTNrespectively indicate the start and end of a sequence of Still_VOBs inthe Still_VOG corresponding to the S_VOGI, thereby indicating theStill_VOBs contained in the still picture cell.

The S_VOGI_SRPN specifies an S_VOGI, thereby specifying Still_VOGcorresponding to the cell.

As described above, the present embodiment uses ORG_PGCI to manage stillpicture cells that constitute still picture sections. As described inEmbodiment 1, the ORG_PGCI manages moving-picture cells. Accordingly, itis possible for Embodiment 7 to manage both moving-picture cells andstill picture cells. FIG. 42 shows an ORG_PGCI that contains informationon a moving-picture section (CELL #1) and a still picture section (CELL#2).

When moving-picture cells and still picture cells are arranged inseries, VOBs and Still_VOGs are arranged in chronological order that isdetermined based on a comparison of FIRST_VOB_REC_TM and LAST_VOB_REC_TMof Still_VOGs and VOB_REC_TM of VOBs. The FIRST_VOB_REC_TM andLAST_VOB_REC_TM of Still_VOGs are based on a time zone specified byTM_ZONE as is the case with VOB_REC_Tm of VOBs. This eliminates the fearthat VOBs and Still_VOGs are improperly arranged because of differenttime zones in which they are recorded. Also, when the data is playedback or a list of the contents is displayed, a recording date/time basedon a time zone in which the data was recorded may be displayed by usingLOCAL_TZ_TY or LOCAL_TZ in LOCAL_TM_ZONE. This provides the same effectsas Embodiment 1.

The above-described embodiments are thought to provide the best effectsat this point of time. However, the present invention can be varied inmany ways and retain the essence of the invention. The following areexamples of such variations of the present invention.

(A) The recording apparatus and playback apparatus described inEmbodiments 2 and 3 are characterized by the operation procedures of thedate/time information setting unit 12 and the date/time display controlunit 20. These characteristic procedures are achieved by the programsstored in the recording apparatus and playback apparatus (see theflowcharts shown in FIGS. 21 and 24). These programs therefore can beexecuted separately from the recording apparatus and playback apparatus.It is also possible to record these programs onto a computer-readablerecording medium and transfer or loan the recording medium so that theprograms can be executed separately. The programs can be distributed ortransferred via a network and can be executed.

There are other characteristics that can be achieved by programs. Theseprograms can also be executed separately from the recording apparatusand playback apparatus.

(B) In Embodiments 1–7, DVD and DVD-RW which conform to the DVD-VIDEORECORDING and on which moving picture data or still picture data can berecorded are used as examples of recording mediums. However, therecording mediums may have any physical structure in so far as movingpicture data or still picture data can be recorded thereon. For example,phase-change type optical discs such as DVD-RW, PD, DVD+RW, and CD-RWmay be used. The following recording mediums can also be used: (i) the“write-once” type optical discs such as CD-R and DVD-R; (ii) themagneto-optical storage type optical discs such as MO (Magneto-Opticaldisc), MD-DAT (Mini Disc Data), and iD format; (iii) the removable harddisc drives such as ORB, Jaz, SparQ, SyJet, EZFley, micro drive; (iv)magnetic recording discs such as floppy disks, SuperDisk, Zip, andClick!; (v) the flash memory cards such as SD memory card, compact flashcard, smart media, memory stick, multimedia card, PCM-CIA card; and (vi)HD(High Density)-DVD that is planned to be standardized.

(C) In the above embodiments, it is presumed that the recordingapparatus 1 is a camcorder. However, the recording apparatus 1 may be astay-at-home DVD recorder such as DMR-E20made by Panasonic.

The recording apparatus 1 may be a personal computer on which a digitalimage editing program such as MotionDV STUDIO or DVD MovieAlbum isinstalled and which is connected to a drive apparatus via an interfaceconforming to SCSI, IDE, or IEEE1394.

(D) In the above embodiments, it is described that video streams andaudio streams are multiplexed into VOBs. However, sub-picture streams orcontrol information may be multiplexed into VOBs as well, where thesub-picture streams are obtained by performing the run-lengthcompression on text data such as subtitles.

(E) In the above embodiments, picture data is played back in units ofvideo frames. In such a case, the relationship between frames andpictures is represented as “1 frame=1 picture” However, the relationshipmay be, for example, “1.5 frame=1 picture” which results fromcompression of the images captured in film intended to be played back ata rate of 24 frames/second.

(F) In the above embodiments, moving picture data is recorded onto anoptical disc in a format conforming to the DVD-VIDEO RECORDING standard.However, moving picture data may be recorded in other formats.

(G) In the above embodiments, moving picture VOBs and still picture VOBsare arranged in chronological order of the recording date/time. However,the VOBs may be arranged in reversed chronological order.

(H) In the above embodiments, VOBs on DVDs are arranged in the order ofrecording date/time. This is a rule unique to the present applicationdocument. In reality, VOBs can be arranged in another order. Forexample, an image editing software program can be used to place a VOBcaptured one month before at a position immediately before a VOBcaptured two days before. However, such a case is rather exceptionalsince this is achieved only when the user intentionally edits the VOBarrangement on DVDs. As a result, in the present application document,it is presumed that VOBs on DVDs are arranged in the order of recordingdate/time.

(I) In the above embodiments, a recording date/time is defined as a timewhen a capturing unit of the recording apparatus starts capturing animage. However, the recording date/time may be defined differently in sofar as it can be accepted by the user. For example, the recordingdate/time may be a time when the recording apparatus starts receiving abroadcast program and recording it onto a DVD, or may be a time when therecording apparatus starts receiving images form an external apparatus.

Although the present invention has been fully described by way ofexamples with reference to the accompanying drawings, it is to be notedthat various changes and modifications will be apparent to those skilledin the art. Therefore, unless such changes and modifications depart fromthe scope of the present invention, they should be construed as beingincluded therein.

1. A recording apparatus for writing a video object onto a recordingmedium on which basic time zone information specifying a basic time zoneis written, the recording apparatus comprising: a timer operable tomeasure a time based on a predetermined time zone; a converting unitoperable to, if the basic time zone does not match the predeterminedtime zone, convert the time measured by the timer into a time based onthe basic time zone; and a writing unit operable to, if the basic timezone does not match the predetermined time zone, write managementinformation for the video object onto the recording medium, themanagement information containing a flag indicating that the basic timezone and the predetermined time zone do not match, recording timeinformation showing the conversion-result time, and local time zoneinformation specifying the predetermined time zone as a local time zone.2. The recording apparatus of claim 1, wherein if the basic time zoneand the predetermined time zone match, the flag in the managementinformation indicates that basic time zone and the predetermined timezone match, and the recording time information shows the time measuredby the timer.
 3. The recording apparatus of claim 2, wherein the basictime zone information shows a time differential between universal timeand a standard time of the basic time zone, and the local time zoneinformation shows a time differential between the universal time and astandard time of the local time zone.
 4. The recording apparatus ofclaim 3, wherein the converting unit is operable to convert the timemeasured by the timer by subtracting the time differential shown in thelocal time zone information from the time measured by the timer andadding the time differential shown in the basic time zone information tothe time measured by the timer.
 5. The playback apparatus for arecording medium on which management information is written, themanagement information containing (a) basic time zone information thatspecifies a basic lime zone, (b) recording time information showing arecording time of a video object, the recording time based on the basictime zone, and (c) a flag, the playback apparatus comprising: a timezone determining unit operable to determine, by referring to the flag,whether a timer of a recording apparatus that recorded the video objectonto the recording medium conforms to the basic time zone or a localtime zone; and a playback unit operable to, if the time zone determiningunit determines that the timer conforms to the local time zone, playback the video object, convert the recording time into a time based onthe local time zone, and display the conversion-result time, wherein thebasic time zone information shows a time differential between universaltime and a standard time of the basic time zone, the local time zoneinformation shows a time differential between the universal time and astandard time of the local time zone, and the playback unit is operableto convert the recording time into the time based on the local time zoneby subtracting the time differential shown in the basic time zoneinformation from the recording time and adding the time differentialshown in the local time zone information to the recording time.
 6. Aprogram recorded on a computer-readable medium for allowing a computerto write a video object onto a recording medium on which basic time zoneinformation specifying a basic time zone is written, the programcomprising: a timer step of measuring a time based on a predeterminedtime zone; a converting step of, if the basic time zone does not matchthe predetermined time zone, converting the time measured by the timerstep into a time based on the basic time zone; and a writing step of, ifthe basic time zone does not match the predetermined time zone, writingmanagement information for the video object onto the recording medium,the management information containing a flag indicating that the basictime zone and the predetermined time zone do not match, time informationshowing the conversion-result, and local time zone informationspecifying the predetermined time zone as a local time zone.
 7. Theprogram of claim 6, wherein if the basic time zone and the predeterminedtime zone match, the flag in the management information indicates thatthe basic time zone and the predetermined time zone match, and the timeinformation shows the time measured by the timer step.
 8. The program ofclaim 7, wherein the basic time zone information shows a timedifferential between universal time and a standard time of the basictime zone, and the local time zone information shows a time differentialbetween the universal time and a standard time of the local time zone.9. The program of claim 8, wherein the converting in the converting stepconverts the time measured by the timer step by subtracting the timedifferential shown in the local time zone information from the timemeasured by the timer step and adding the time differential shown in thebasic time zone information to the time measured by the timer step. 10.A program recorded on a computer-readable recording medium for allowinga computer to execute a playback procedure for a recording medium onwhich management information is written, the management informationcontaining (a) basic time zone information that specifies a basic timezone, (b) recording time information showing a recording time of a videoobject, the recording time based on the basic time zone, and (c) a flag,the program comprising: a time zone determining step of determining, byreferring to the flag, whether a timer of a recording apparatus thatrecorded the video object onto the recording medium conforms to thebasic time zone or a local time zone; and a playback step of, if thetime zone determining step determines that the timer conforms to thelocal time zone, playing back the video object, converting the recordingtime into a time based on the local time zone, and displaying theconversion-result time, wherein the basic time zone information shows atime differential between universal time and a standard time of thebasic time zone, the local time zone information shows a timedifferential between the universal time and a standard time of the localtime zone, and the converting in the playback step converts therecording time into the time based on the local time zone by subtractingthe time differential shown in the basic time zone information from tothe recording time and adding the time differential shown in the localtime zone information to the recording time.
 11. A recording method forwriting a video object onto a recording medium on which basic time zoneinformation specifying a basic time zone is written, the recordingmethod comprising: a timer step of measuring a time based on apredetermined time zone; a converting step of, if the basic time zonedoes not match the predetermined time zone, converting the time measuredby the timer step into a time based on the basic time zone; and awriting step of, if the basic time zone does not match the predeterminedtime zone, writing management information for the video object onto therecording medium, the management information containing a flagindicating that the basic time zone and the predetermined time zone donot match, recording time information showing the conversion-resulttime, and local time zone information specifying the predetermined timezone as a local time zone.
 12. A playback method for a recording mediumon which management information is written, the management informationcontaining (a) basic time zone information that specifies a basic timezone, (b) recording time information showing a recording time of a videoobject, the recording time based on the basic time zone, and (c) a flag,the playback method comprising: a time zone determining step ofdetermining, by referring to the flag, whether a timer of a recordingapparatus that recorded the video object onto the recording mediumconforms to the basic time zone or a local time zone; and a playbackstep of, if the time zone determining step determines that the timerconforms to the local time zone, playing back the video object,converting the recording time into a time based on the local time zone,and displaying the conversion-result time, wherein the basic time zoneinformation shows a time differential between universal time and astandard time of the basic time zone, the local time zone informationshows a time differential between the universal time and a standard timeof the local time zone, and the converting in the playback step convertsthe recording time into the time based on the local time zone bysubtracting the time differential shown in the basic time zoneinformation from and adding the time differential shown in the localtime zone information to the recording time.